diff --git a/hphp/compiler/analysis/analysis_result.cpp b/hphp/compiler/analysis/analysis_result.cpp
index 06e108c4d..9ec130058 100644
--- a/hphp/compiler/analysis/analysis_result.cpp
+++ b/hphp/compiler/analysis/analysis_result.cpp
@@ -423,6 +423,16 @@ void AnalysisResult::markRedeclaringClasses() {
     }
   }
 
+  auto markRedeclaring = [&] (const std::string& name) {
+    auto it = m_classDecs.find(name);
+    if (it != m_classDecs.end()) {
+      auto& classes = it->second;
+      for (unsigned int i = 0; i < classes.size(); ++i) {
+        classes[i]->setRedeclaring(ar, i);
+      }
+    }
+  };
+
   /*
    * In WholeProgram mode, during parse time we collected all
    * class_alias calls so we can mark the targets of such calls
@@ -446,19 +456,19 @@ void AnalysisResult::markRedeclaringClasses() {
    * as redeclaring for now.
    */
   for (auto& kv : m_classAliases) {
-    auto markRedeclaring = [&] (const std::string& name) {
-      auto it = m_classDecs.find(name);
-      if (it != m_classDecs.end()) {
-        auto& classes = it->second;
-        for (unsigned int i = 0; i < classes.size(); ++i) {
-          classes[i]->setRedeclaring(ar, i);
-        }
-      }
-    };
-
     markRedeclaring(Util::toLower(kv.first));
     markRedeclaring(Util::toLower(kv.second));
   }
+
+  /*
+   * Similar to class_alias, when a type alias is declared with the
+   * same name as a class in the program, we need to make sure the
+   * class is marked redeclaring.  It is possible in some requests
+   * that things like 'instanceof Foo' will not mean the same thing.
+   */
+  for (auto& name : m_typeAliasNames) {
+    markRedeclaring(Util::toLower(name));
+  }
 }
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -643,6 +653,8 @@ void AnalysisResult::collectFunctionsAndClasses(FileScopePtr fs) {
 
   m_classAliases.insert(fs->getClassAliases().begin(),
                         fs->getClassAliases().end());
+  m_typeAliasNames.insert(fs->getTypeAliasNames().begin(),
+                          fs->getTypeAliasNames().end());
 }
 
 static bool by_filename(const FileScopePtr &f1, const FileScopePtr &f2) {
diff --git a/hphp/compiler/analysis/analysis_result.h b/hphp/compiler/analysis/analysis_result.h
index 3a4a84594..d77f9bd21 100644
--- a/hphp/compiler/analysis/analysis_result.h
+++ b/hphp/compiler/analysis/analysis_result.h
@@ -324,6 +324,9 @@ private:
   // Only in WholeProgram mode.  See markRedeclaringClasses.
   std::multimap<std::string,std::string> m_classAliases;
 
+  // Names of type aliases.
+  std::set<std::string> m_typeAliasNames;
+
   bool m_classForcedVariants[2];
 
   StatementPtrVec m_stmts;
diff --git a/hphp/compiler/analysis/file_scope.h b/hphp/compiler/analysis/file_scope.h
index add19363c..378b79b1f 100644
--- a/hphp/compiler/analysis/file_scope.h
+++ b/hphp/compiler/analysis/file_scope.h
@@ -145,6 +145,14 @@ public:
     return m_classAliasMap;
   }
 
+  void addTypeAliasName(const std::string& name) {
+    m_typeAliasNames.insert(name);
+  }
+
+  std::set<std::string> const& getTypeAliasNames() const {
+    return m_typeAliasNames;
+  }
+
   /**
    * Called only by World
    */
@@ -217,6 +225,11 @@ private:
   // This is only needed in WholeProgram mode.
   std::multimap<std::string,std::string> m_classAliasMap;
 
+  // Set of names that are on the left hand side of type alias
+  // declarations.  We need this to make sure we don't mark classes
+  // with the same name Unique.
+  std::set<std::string> m_typeAliasNames;
+
   FunctionScopePtr createPseudoMain(AnalysisResultConstPtr ar);
   void setFileLevel(StatementListPtr stmt);
 };
diff --git a/hphp/compiler/parser/parser.cpp b/hphp/compiler/parser/parser.cpp
index c07c97258..cdc0fb8ad 100644
--- a/hphp/compiler/parser/parser.cpp
+++ b/hphp/compiler/parser/parser.cpp
@@ -1634,7 +1634,9 @@ void Parser::onGoto(Token &out, Token &label, bool limited) {
 }
 
 void Parser::onTypedef(Token& out, const Token& name, const Token& type) {
-  out->stmt = NEW_STMT(TypedefStatement, name.text(), type.text());
+  auto td_stmt = NEW_STMT(TypedefStatement, name.text(), type.text());
+  td_stmt->onParse(m_ar, m_file);
+  out->stmt = td_stmt;
 }
 
 void Parser::onTypeAnnotation(Token& out, const Token& name,
diff --git a/hphp/compiler/statement/typedef_statement.cpp b/hphp/compiler/statement/typedef_statement.cpp
index 826324a62..e83401bda 100644
--- a/hphp/compiler/statement/typedef_statement.cpp
+++ b/hphp/compiler/statement/typedef_statement.cpp
@@ -15,6 +15,8 @@
 */
 #include "hphp/compiler/statement/typedef_statement.h"
 
+#include "hphp/compiler/analysis/file_scope.h"
+
 namespace HPHP {
 
 //////////////////////////////////////////////////////////////////////
@@ -57,6 +59,10 @@ void TypedefStatement::inferTypes(AnalysisResultPtr) {}
 void TypedefStatement::outputPHP(CodeGenerator& cg, AnalysisResultPtr ar) {
 }
 
+void TypedefStatement::onParse(AnalysisResultConstPtr ar, FileScopePtr scope) {
+  scope->addTypeAliasName(name);
+}
+
 //////////////////////////////////////////////////////////////////////
 
 }
diff --git a/hphp/compiler/statement/typedef_statement.h b/hphp/compiler/statement/typedef_statement.h
index f81c91d5c..1466654cd 100644
--- a/hphp/compiler/statement/typedef_statement.h
+++ b/hphp/compiler/statement/typedef_statement.h
@@ -25,7 +25,7 @@
 namespace HPHP {
 //////////////////////////////////////////////////////////////////////
 
-struct TypedefStatement : Statement {
+struct TypedefStatement : Statement, IParseHandler {
   explicit TypedefStatement(STATEMENT_CONSTRUCTOR_PARAMETERS,
                             const std::string& name,
                             const std::string& value);
@@ -33,6 +33,10 @@ struct TypedefStatement : Statement {
 
   DECLARE_STATEMENT_VIRTUAL_FUNCTIONS;
 
+public: // IParseHandler
+  void onParse(AnalysisResultConstPtr, FileScopePtr);
+
+public:
   const std::string name;
   const std::string value;
 };